Integration of public health and health services evaluation measures: The case for standardizing reach and dose

Background: The concepts of the ‘reach’ (i.e., the proportion of a population exposed to an intervention) and ‘dose’ (i.e., the intensity of a participant’s exposure to the intervention) of an intervention are important evaluation criteria in the field of public health but are less prominent in health services research. The target population of an intervention can be at the organization, setting, or population level but is often not specified as well as needed for the evaluation design. There is no standard or widely accepted definition of treatment intensity in the health services field that helps to quantify the degree to which increasing exposure impacts specific outcomes. Instead, exposure to the intervention is typically dichotomous (i.e., treatment group or not). This treatment exposure measurement can lead to ambiguous conclusions about the effectiveness of an intervention. This challenge was encountered in designing the evaluation of 24 Health Care Innovation Awardees of the Centers for Medicare and Medicaid Innovation and solutions were implemented that will be described.

Methods: Qualitative data from awardees are compared to aggregated quantitative data provided by awardees via their electronic medical records or administrative data.

Results: Few of the 24 awardees provided data on the potential reach of their interventions and had difficulty defining their target populations. Even fewer awardees were collecting measures of dose that could be used to assess exposure to the interventions.

Conclusions: We present an assessment of the reach and dose measures used across the 24 awardees, the challenges of conceptualizing these measures and offer recommendations for standardizing these measures.